Bad weather in January hit passenger numbers at BAA airports, marring an improvement in the overall trend, the airport operator said.

At Heathrow there was a drop of 0.5% in passenger numbers compared with the same month last year. But without the bad weather causing the loss of around 145,000 passengers at the airport, traffic would have grown by an estimated 2.5%.

Figures for BAA as a whole showed a drop of 3.1% to 7.2 million passengers in January. Without the disruption it is estimated the drop would have been 0.3%.

At Stansted the drop was 5.6%; at Southampton 9.7%; Glasgow 12.2%; Edinburgh 7.4%; Aberdeen 13.6%. BAA said at each airport a significant part of the drop can be attributed to the snow. 

Glasgow and Edinburgh were also impacted by the collapse of Flyglobespan, as they were in December.

BAA chief executive Colin Matthews said: "There is no doubt the market remains a difficult one, and certainly the snow didn't help, but, equally, there were encouraging signs of growth, particularly on the routes out of Heathrow to the Middle East and South America."